First Class: Property value is True or False
Android:layout_centerhrizontal Horizontal Center
Android:layout_centervertical Vertical Center
Android:layout_centerinparent is completely centered relative to the parent element
Android:layout_alignparentbottom snaps to the bottom edge of the parent element
Android:layout_alignparentleft snaps to the left edge of the parent element
Android:layout_alignparentright snaps to the right edge of the parent element
Android:layout_alignparenttop snaps to the top edge of the parent element
android:layout_alignwithparentifmissing if the corresponding sibling element cannot be found, then the parent element is the reference.
Second class: The attribute value must be the reference name of the id "@id/id-name"
Android:layout_below at the bottom of an element
Android:layout_above at the top of an element
Android:layout_toleftof on the left side of an element
Android:layout_torightof on the right side of an element
Android:layout_aligntop aligns the top edge of this element with the top edge of an element
Android:layout_alignleft aligns the left edge of this element with the left edge of an element
Android:layout_alignbottom aligns the bottom edge of this element with the bottom edge of an element
Android:layout_alignright aligns the right edge of this element with the right edge of an element
Class III: Attribute values are specific pixel values, such as 30dip,40px
Android:layout_marginbottom distance from the bottom edge of an element
Android:layout_marginleft distance from the left edge of an element
Android:layout_marginright distance from the right edge of an element
Android:layout_margintop distance from the top edge of an element
EditText's Android:hint
Sets the prompt information in the input box when EditText is empty.
android:gravity
The Android:gravity property is the qualification for the view content. For example, a button above the text. You can set the text on the left side of the view, on the right, and so on. Take the button as an example, android:gravity= "right" then the text on the button
android:layout_gravity
Android:layout_gravity is used to set the position of the view relative to the parent view. For example, a button in the LinearLayout, you want to put the button on the left, right and other positions can be set by this property. Take button For example, android:layout_gravity= "right" button on
Android:layout_alignparentright
Aligns the right end of the current control with the right end of the parent control. This property value can only be true or FALSE, which is false by default.
Android:scaletype:
Android:scaletype is a size that controls how the picture resized/moved to the ImageView. The meaning difference of Imageview.scaletype/android:scaletype value:
Center/center is centered on the original size of the image, and when the picture is longer/wider than the length/width of the view, the center portion of the image is displayed
Center_crop/centercrop proportionally enlarges the size of the image so that the image is long (wide) equal to or greater than the length (width) of the view
Center_inside/centerinside Displays the contents of the picture in full, by scaling it down or the original size to make the picture long/wide equal to or less than the length/width of the view
Fit_center/fitcenter enlarge/Shrink the picture to the width of the view, centered on the display
Fit_end/fitend Zoom in/out to the width of the view, displayed in the lower part of the view
Fit_start/fitstart enlarge/Shrink the image to the width of the view, displayed in the upper part of the view
Fit_xy/fitxy The picture is not scaled up/down to the view size display
The Matrix/matrix is drawn with a matrix and is displayed by zooming in and out of the image.
* * To note that the Drawable folder inside the image name can not be capitalized
Property explained in detail